TY - JOUR
T1 - The XMM-LSS survey
T2 - The Class 1 cluster sample over the initial 5 deg 2 and its cosmological modelling
AU - Pacaud, F.
AU - Pierre, M.
AU - Adami, C.
AU - Altieri, B.
AU - Andreon, S.
AU - Chiappetti, L.
AU - Detal, A.
AU - Duc, P. A.
AU - Galaz, G.
AU - Gueguen, A.
AU - Le Fèvre, J. P.
AU - Hertling, G.
AU - Libbrecht, C.
AU - Melin, J. B.
AU - Ponman, T. J.
AU - Quintana, H.
AU - Refregier, A.
AU - Sprimont, P. G.
AU - Surdej, J.
AU - Valtchanov, I.
AU - Willis, J. P.
AU - Alloin, D.
AU - Birkinshaw, M.
AU - Bremer, M. N.
AU - Garcet, O.
AU - Jean, C.
AU - Jones, L. R.
AU - Le Fèvre, O.
AU - MacCagni, D.
AU - Mazure, A.
AU - Proust, D.
AU - Röttgering, H. J.A.
AU - Trinchieri, G.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - We present a sample of 29 galaxy clusters from the XMM-LSS survey over an area of some 5 deg2 out to a redshift of z = 1.05. The sample clusters, which represent about half of the X-ray clusters identified in the region, follow well-defined X-ray selection criteria and are all spectroscopically confirmed. For all clusters, we provide X-ray luminosities and temperatures as well as masses, obtained from dedicated spatial and spectral fitting. The cluster distribution peaks around z = 0.3 and T = 1.5 keV, half of the objects being groups with a temperature below 2 keV. Our LX-T(z) relation points towards self-similar evolution, but does not exclude other physically plausible models. Assuming that cluster scaling laws follow self-similar evolution, our number density estimates up to z = 1 are compatible with the predictions of the concordance cosmology and with the findings of previous ROSAT surveys. Our well-monitored selection function allowed us to demonstrate that the inclusion of selection effects is essential for the correct determination of the evolution of the LX-T relation, which may explain the contradictory results from previous studies. Extensive simulations show that extending the survey area to 10 deg2 has the potential to exclude the non-evolution hypothesis, but those constraints on more refined intracluster medium models will probably be limited by the large intrinsic dispersion of the LX-T relation, whatever be the sample size. We further demonstrate that increasing the dispersion in the scaling laws increases the number of detectable clusters, hence generating further degeneracy [in addition to σ8, Ωm, LX-T(z)] in the cosmological interpretation of the cluster number counts. We provide useful empirical formulae for the cluster mass-flux and mass-count rate relations as well as a comparison between the XMM-LSS mass sensitivity and that of forthcoming Sunyaev-Zel'dovich surveys.
AB - We present a sample of 29 galaxy clusters from the XMM-LSS survey over an area of some 5 deg2 out to a redshift of z = 1.05. The sample clusters, which represent about half of the X-ray clusters identified in the region, follow well-defined X-ray selection criteria and are all spectroscopically confirmed. For all clusters, we provide X-ray luminosities and temperatures as well as masses, obtained from dedicated spatial and spectral fitting. The cluster distribution peaks around z = 0.3 and T = 1.5 keV, half of the objects being groups with a temperature below 2 keV. Our LX-T(z) relation points towards self-similar evolution, but does not exclude other physically plausible models. Assuming that cluster scaling laws follow self-similar evolution, our number density estimates up to z = 1 are compatible with the predictions of the concordance cosmology and with the findings of previous ROSAT surveys. Our well-monitored selection function allowed us to demonstrate that the inclusion of selection effects is essential for the correct determination of the evolution of the LX-T relation, which may explain the contradictory results from previous studies. Extensive simulations show that extending the survey area to 10 deg2 has the potential to exclude the non-evolution hypothesis, but those constraints on more refined intracluster medium models will probably be limited by the large intrinsic dispersion of the LX-T relation, whatever be the sample size. We further demonstrate that increasing the dispersion in the scaling laws increases the number of detectable clusters, hence generating further degeneracy [in addition to σ8, Ωm, LX-T(z)] in the cosmological interpretation of the cluster number counts. We provide useful empirical formulae for the cluster mass-flux and mass-count rate relations as well as a comparison between the XMM-LSS mass sensitivity and that of forthcoming Sunyaev-Zel'dovich surveys.
KW - Cosmological parameters
KW - Large-scale structure of Universe
KW - Surveys
KW - X-rays: galaxies: clusters
UR - http://www.scopus.com/inward/record.url?scp=36549025313&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2007.12468.x
DO - 10.1111/j.1365-2966.2007.12468.x
M3 - Article (Academic Journal)
AN - SCOPUS:36549025313
VL - 382
SP - 1289
EP - 1308
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 3
ER -